On the basis of recent clinical data suggesting that high-dose continuous 5-fluorouracil (5-FU) is able to overcome resistance to 5-FU bolus application in gastric carcinoma, a phase II study was performed to evaluate the activity and toxicity of weekly high-dose 5-FU and leucovorin plus biweekly alternating doxorubicin and cisplatin as the first-line treatment in patients with advanced gastric carcinoma. Between October 1995 and September 1997, 24 consecutive patients with locally advanced (n=4) or metastatic (n=20) gastric carcinomas were treated with a combination of 500 mg/m2 leucovorin as a 2-h infusion, followed by 2.0 g/m2 5-FU as a 24-h continuous infusion once weekly for 6 weeks, plus 20 mg/m2 doxorubicin as a bolus application and 50 mg/m2 cisplatin as a 1-h infusion, week 1, 3 and 5 (FLAP regimen). Response, toxicity and survival data were evaluated. A total of 20 patients were evaluable for response and 24 for toxicity. Objective responses were observed in 11 patients (55%) with no complete remission. Four patients (20%) showed stabilization and 5 patients (25%) experienced progressive disease. The median time to disease progression was 8 months and the overall duration of survival was 14 months. Myelosuppression was significant. In 2 patients, grade 4 WHO thrombocytopenia and leukopenia/anaemia respectively were registered, but there were no treatment-related deaths. We conclude that the weekly alternating FLAP regimen is effective in advanced gastric carcinoma with tolerable toxicity. However, significant myelotoxicity and frequent hospitalization suggest that FLAP should not be preferred to other regimens used in metastatic disease. Currently we intend to establish this regimen in the neoadjuvant setting in patients with primary unresectable localized gastric carcinomas.